224 related to Vincigiierria, Jordan and Evermann ; this is seen inter alia, in the position of the fins, position and formation of the photophores, dentition, gill-rakers etc. Diplophos tænia, Giinther (Fig. 14). Of this species, we have abt. 40 specimens from a length of 17 mm (postlarva with diphycercal tail) to adult stages of 48 mm ex. C. When the postlarva has reached a length of abt. 46 mm, the photophores commence to form, and at the same time, a great reduction in length takes place, with up to Vs of the total length. The pigmentation of the postlarvæ is, as shown in the figure, very characteristic, and remains of the postlarval pigment are found in the adolescent stages. The specimens were taken chiefly at the surface. In the area investigated of the Atlantic, the principal distribution lies south of 40" N. Lat., and west of 40° W. Long, though some specimens were found eastward to 20 "^ 36' W. Long. Diplophos minutus, nov. sp. (Fig. 15). Of this species we have some ten individuals, the largest meas- uring 21 mm ex. C. The proportions etc. will be seen from the accompanying sketch. The species seems to be more nearly re- lated to Diplophos pacificus, Gunther than Diplophos lænia, Gun- ther. All the specimens exhibit diffuse pigment, and have only little of the postlarval appearance remaining. Probably, not all the photophores have been formed on the head (cf. Diplophos tænia). N. of fin rays: D 10-12, A 37—39, P 9, V 8, C 6 + (10 -|-9)-|-4. Gill-rakers in 1. branchial arch: 4-|-7-|-2. Photophores: Orb. 2, Op 1 -f"2, SO 1, (there is also one other organ on the lower jaw, a little farther back), Br 9, I O 30, VO 1 + 1 • — 12 (the foremost lies between the ventral fins), AO 28— 30, PO 1, LO I 46—47, LO II 65—66. The species was taken in the upper water layers, and in the area investigated, it was only found in that part of the Northern Atlantic which lies south of 40" N. Lat. and west of 50° W. Long. Valenciennellus tripunctulatus, Esmark (Fig. 16). This very characteristic species resembles, in the postlarva, the Sternoptychid-larva B, but is easily distinguished therefrom by the ?
225 oval eye and the faet that the Br organs are first formed. (Cf. Brauer (1906) p. 101, fig. 42). The species is fairly commonly distributed from the Bay of Cadiz in the North Atlantic south of abt. 40 "^ N. Lat. ; like several other species, it is found somewhat farther north nearer the American side. In the foregoing, the following abbreviations have been employed. The number of gill-rakers has only been noted for the first branchial arch, and the figures indicate : number situated on epibranchiale + n. on ceratobranch- iale + n. on hypobranchiale e. g. 5 + 9 -r 5\ The abbreviations for photophores are as foliows : Orb. indicates organs situated in the region of the eye. Op on the operculum, S O at the symph- ysis of the lower jaw, Br on the branchiostegal membrane, 1 O on the isthmus and abdomen to the ventral fin V, BO organs on the abdomen alone (from the head to the V, VO between V and the anal fin A), CO from the anterior margin of the A to the caudal fin (C), LO organs situated laterally, LO I lowest, LO II upper lateral row , PO at base of the pectoral fin P . D indicates the dorsal fin. Explanation of the Plate XVII. 1.*) Vinciguerria Poweriæ, (Cocco). Adulescent stage, 21.8 mm ex. C; „Thor", St. 158, •' 7 10, 300 m w. out. 2. — Sanzoi, sp. nov. Adolescent stage, 20.3 mm ex. C; „Thor", St. 231, »9 10, 25 m w. out. 3. — a^^enuflto, (Cocco). Adolescent stage, 20.8 mm ex. C; „Thor", St. 46, " 2 09, 600 m w. out. 4. — Poweriæ, Cocco). Postiarval stage, 20 mm ex. C; „Thor", St. 186, " 8 10. 65 m. w. out. 5. — Sanzoi, sp. nov. Postiarval stage, 14..i mm ex. C; „Mar- grethe", St. 1068, 'V 12 13, 65 m w. out. 6. — attenuata (Cocco). Postiarval stage, 18 s mm ex. C; „Thor", St. 132, "7 10, 300 m w. out. ') The dotted line in figs. 1—3 indicates the abdominal cavity. Photophores situated on the isthmus, the branchiostegal membrane etc. (e. g. photo- phores only visible through the operculum etc.) are indicated in an other way than the remainder photophores. Vidensk. Medd. fra Dansk naturh. Foren. Bd. 70. 15